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Bandpass filter specification object

`D = fdesign.bandpass`

D = fdesign.bandpass(SPEC)

D = fdesign.bandpass(spec,specvalue1,specvalue2,...)

D = fdesign.bandpass(specvalue1,specvalue2,specvalue3,

specvalue4,...specvalue4,specvalue5,specvalue6)

D = fdesign.bandpass(...,Fs)

D = fdesign.bandpass(...,MAGUNITS)

`D = fdesign.bandpass`

constructs
a bandpass filter specification object `D`

, applying
default values for the properties `Fstop1`

, `Fpass1`

, `Fpass2`

, `Fstop2`

, `Astop1`

, `Apass`

,
and `Astop2`

— one possible set of values
you use to specify a bandpass filter.

`D = fdesign.bandpass(SPEC)`

constructs
object `D`

and sets its `Specification`

property
to `SPEC`

. Entries in the `SPEC`

represent
various filter response features, such as the filter order, that govern
the filter design. Valid entries for `SPEC`

are shown
below and used to define the bandpass filter. These entries are not
case sensitive.

Specifications marked with an asterisk require the DSP System Toolbox™ software.

`'Fst1,Fp1,Fp2,Fst2,Ast1,Ap,Ast2'`

(default`spec`

)`'N,F3dB1,F3dB2'`

`"N,F3dB1,F3dB2,Ap'`

*`'N,F3dB1,F3dB2,Ast'`

*`'N,F3dB1,F3dB2,Ast1,Ap,Ast2'`

*`'N,F3dB1,F3dB2,BWp`

*`'N,F3dB1,F3dB2,BWst'`

*`'N,Fc1,Fc2'`

`'N,Fc1,Fc2,Ast1,Ap,Ast2'`

`'N,Fp1,Fp2,Ap'`

`'N,Fp1,Fp2,Ast1,Ap,Ast2'`

`'N,Fst1,Fp1,Fp2,Fst2'`

`'N,Fst1,Fp1,Fp2,Fst2,C'`

*`'N,Fst1,Fp1,Fp2,Fst2,Ap'`

*`'N,Fst1,Fst2,Ast'`

`'Nb,Na,Fst1,Fp1,Fp2,Fst2'`

*

The filter specifications are defined as follows:

`Ap`

— amount of ripple allowed in the pass band. Also called Apass.`Ast1`

— attenuation in the first stop band in decibels (the default units). Also called Astop1.`Ast2`

— attenuation in the second stop band in decibels (the default units). Also called Astop2.`BWp`

— bandwidth of the filter passband. Specified in normalized frequency units.`BWst`

— bandwidth of the filter stopband. Specified in normalized frequency units.`C`

— Constrained band flag. This enables you to specify passband ripple or stopband attenuation for fixed-order designs in one or two of the three bands.In the specification

`'N,Fst1,Fp1,Fp2,Fst2,C'`

, you cannot specify constraints in both stopbands and the passband simultaneously. You can specify constraints in any one or two bands.`F3dB1`

— cutoff frequency for the point 3 dB point below the passband value for the first cutoff. Specified in normalized frequency units. (IIR filters)`F3dB2`

— cutoff frequency for the point 3 dB point below the passband value for the second cutoff. Specified in normalized frequency units. (IIR filters)`Fc1`

— cutoff frequency for the point 6 dB point below the passband value for the first cutoff. Specified in normalized frequency units. (FIR filters)`Fc2`

— cutoff frequency for the point 6 dB point below the passband value for the second cutoff. Specified in normalized frequency units. (FIR filters)`Fp1`

— frequency at the edge of the start of the pass band. Specified in normalized frequency units. Also called Fpass1.`Fp2`

— frequency at the edge of the end of the pass band. Specified in normalized frequency units. Also called Fpass2.`Fst1`

— frequency at the edge of the start of the first stop band. Specified in normalized frequency units. Also called Fstop1.`Fst2`

— frequency at the edge of the start of the second stop band. Specified in normalized frequency units. Also called Fstop2.`N`

— filter order for FIR filters. Or both the numerator and denominator orders for IIR filters when na and nb are not provided.`Na`

— denominator order for IIR filters`Nb`

— numerator order for IIR filters

Graphically, the filter specifications look similar to those shown in the following figure.

Regions between specification values like `Fst1`

and `Fp1`

are
transition regions where the filter response is not explicitly defined.

The filter design methods that apply to a bandpass filter specification
object change depending on the `Specification`

. Use `designmethods`

to determine which design
methods apply to an object and the `Specification`

property
value.

Use `designopts`

to determine
the design options for a given design method. Enter `help(D,METHOD)`

at
the MATLAB^{®} command line to obtain detailed help on the design
options for a given design method, `METHOD`

.

`D = fdesign.bandpass(spec,specvalue1,specvalue2,...)`

constructs
an object `D`

and sets its specifications at construction
time.

`D = fdesign.bandpass(specvalue1,specvalue2,specvalue3,`

constructs

specvalue4,...specvalue4,specvalue5,specvalue6)`D`

with
the default `Specification`

property, using the values
you provide as input arguments for ```
specvalue1,specvalue2,specvalue3,specvalue4,specvalue4,specvalue5,
specvalue6
```

and `specvalue7`

.

`D = fdesign.bandpass(...,Fs)`

adds
the argument `Fs`

, specified in Hz to define the
sampling frequency to use. In this case, all frequencies in the specifications
are in Hz as well.

`D = fdesign.bandpass(...,MAGUNITS)`

specifies
the units for any magnitude specification you provide in the input
arguments. `MAGUNITS`

can be one of

`'linear'`

— specify the magnitude in linear units`'dB'`

— specify the magnitude in dB (decibels)`'squared'`

— specify the magnitude in power units

When you omit the `MAGUNITS`

argument, `fdesign`

assumes
that all magnitudes are in decibels. Note that `fdesign`

stores
all magnitude specifications in decibels (converting to decibels when
necessary) regardless of how you specify the magnitudes.

`fdesign`

| `fdesign.bandstop`

| `fdesign.highpass`

| `fdesign.lowpass`

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